The present invention relates to an optical pickup dustproofing mechanism applied to a disc device, comprising: a turn table on which a disc such as a compact disc or the like is placed; an optical pickup, which provides an objective lens for converging light on a disc and which moves in a radial direction with the turn table as a center point; and a chucking member, which is disposed so as to correspond to the turn table and which clamps the disc in a horizontal direction with the turn table. More particularly, the present invention rotates to an optical pickup dustproofing mechanism that prevents adhesion of dust or the like to the objective lens positioned in a standby position.
For example, among sound apparatuses such as radio cassette recorders having disc devices or the like, there are sound apparatuses in which a disc device is disposed at an upper portion of the sound apparatus. The cover of the disc device is disposed at an upper panel of a main body of the sound apparatus, and a storing portion storing therein a disc is opened or closed due to rotation of this cover.
When the cover of the disc device is open, dust or the like floating in the air (which is simply referred to as xe2x80x9cdustxe2x80x9d hereinafter) enters into the storing portion and may adhere to an objective lens of an optical pickup. If dust adheres to the objective lens, the amount of light transmitted from the objective lens and the amount of light reflected from the disc decreases, which may cause reading failure (regeneration failure) of a photodetector, which detects signals from reflected light.
Therefore, among conventional disc devices, in order to prevent adhesion of dust or the like to the objective lens, there are provided some disc devices in which a shielding member is disposed at an upper portion of the optical pickup, and stoppers and springs for controlling operation of this shielding member are also provided (refer to Japanese Patent Application Laid-Open (JP-A) No. 6-274915). In this dustproofing mechanism, when the optical pickup is withdrawn to its standby position, the shielding member rotates toward a side of the objective lens so as to shield the objective lens.
However, in the above-described dustproofing mechanism of the optical pickup, since it is necessary to provide the stoppers and the springs in addition to the shielding member, the number of components increases and a structure becomes more complicated, which may cause increased costs and failures. Further, in a case of a portable disc device or the like, the optical pickup positioned in the standby position may move due to a receiving a strong impact, and a problem may be caused wherein the shielding member is held in an open state.
In view of the aforementioned facts, it is an object of the present invention to provide an optical pickup dustproofing mechanism having a simple structure in which an objective lens is shielded promptly and reliably so as to prevent adhesion of dust or the like to the objective lens.
A first embodiment of the present invention is an optical pickup dustproofing mechanism applied to a disc device, comprising: a turn table on which a disc is placed; an optical pickup which provides an objective lens for converging light on the disc and which moves in a radial direction with the turn table as a center point; and a chucking member which is disposed so as to correspond to the turn table and which clamps the disc in a horizontal direction between the turn table and the chucking member; wherein the optical pickup dustproofing mechanism has a dustproofing member movable along a substantially shaft center direction of the chucking member, and is connected to the chucking member so as to face a standby position the optical pickup.
In accordance with the first embodiment of the present invention, when the disc is placed on the turn table, the dustproofing member abuts the disc, and in this state, the disk is played back or recorded upon. Meanwhile, in a case in which the disc is not placed on the turn table, the dustproofing member moves along the substantially shaft center direction of the chucking member so as to shield the objective lens positioned in the standby position.
In accordance with the first embodiment of the present invention, since adhesion of dust or the like to the objective lens is prevented, for example, the amount of light transmitted onto a photodetector does not decrease and reading failure is prevented. Further, in accordance with the present invention, a structure is adopted wherein the dustproofing member is simply connected to the chucking member, as compared to a conventional dustproofing member, the number of components decreases, the structure is simplified, the dustproofing mechanism of the optical pickup becomes low cost, and failures are minimized.
Further, in accordance with the first embodiment, in a case in which a strong impact acts on the disc device, simply by a movable portion moving vertically, adhesion of dust or the like to the objective lens is reliably prevented since the movable portion moves downwardly due to its own weight and shields the objective lens.
A second embodiment includes an optical pickup dustproofing mechanism, wherein the dustproofing member includes an extending piece formed at a fixing portion of the chucking member and a movable portion disposed so as to be able to move with respect to the extending piece.
A third embodiment includes an optical pickup dustproofing mechanism, wherein concave-convex portions are formed on respective surfaces facing each other of the extending piece of the fixing portion and of the movable portion, so as to be symmetrical with each other.
Since the concave-convex portions are formed on the respective surfaces facing each other of the extending piece and of the movable portion so as to be symmetrical with each other, the concave-convex portion of the movable portion is guided by the concave-convex portion of the extending piece, and the extending piece and the movable portion are positioned in a state in which the concave-convex portions of the movable portion and of the extending piece correspond to each other. Therefore, in accordance with the third embodiment of the present invention, the movable portion engages with the extending piece promptly and precisely, and therefore, looseness of the movable portion when the disc rotates can be prevented.
In a fourth embodiment, an optical pickup dustproofing mechanism, wherein the circumferential cross-sectional configuration of each of the concave-convex portions is formed in a V-shape.
In a fifth embodiment, an optical pickup dustproofing mechanism, wherein the disc is a compact disc.
A sixth embodiment of the present invention is an optical pickup dustproofing mechanism applied to a disc device, comprising: a turn table on which a disc is placed; an optical pickup which provides an objective lens for converging light on the disc and which moves in a radial direction with the turn table as a center point; and a chucking member which is disposed so as to correspond to the turn table and which clamps the disc in a horizontal direction between the turn table and the chucking member; wherein the optical pickup dustproofing mechanism has a dustproofing member movable along a substantially shaft center direction of the chucking member, and is connected to the chucking member so as to face a standby position of the optical pickup, and further comprises urging means which urges the dustproofing member toward a side of the optical pickup and which is provided between the dustproofing member and the chucking member.
Since the dustproofing mechanism is formed merely by the dustproofing member which is disposed at the chucking member and the urging means which urges the dustproofing member toward the optical pickup, as compared to a conventional dustproofing mechanism, the number of components decreases, the structure is simplified, the dustproofing mechanism of the optical pickup becomes low cost, and failures are minimized. Further, the dustproofing mechanism of the present invention can be applied to a type of disc device in which the disc is clamped in a perpendicular (vertical) direction between the chucking member and the turn table. When a strong impact acts upon the disc device, since the dustproofing member is urged toward the side of the optical pickup by the urging means and shields the objective lens, adhesion of dust or the like to the objective lens is reliably prevented.
A seventh embodiment includes an optical pickup dustproofing mechanism, wherein the urging means is a coil spring.
An eighth embodiment includes an optical pickup dustproofing mechanism, wherein the disc is a compact disc.